FO1-3

LNG Interchangeability––Residential Field Studies and Sensitive Industrial Burner Tests

> Neil Leslie - presenter R&D Director, End Use Solutions Gas Technology Institute

> International Gas Union Research Conference 19 September 2014

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Interchangeability Defined

> The ability to substitute one gaseous fuel for another in a combustion application without materially changing operational safety or performance and without materially increasing air pollutant emissions

Source – NGC+ Working Group on Interchangeability White Paper presented to FERC, Feb. 2005

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Program Objective

> To provide information to policymakers, regulators and industry such as on the potential safety, performance and air quality impacts of increased variability in the California natural gas supply, and specifically related to the use of LNG

> Combustion systems studied include: ─ Industrial combustion systems ─ Commercial cooking appliances ─ Residential appliances

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Industrial Burner and Cooking Appliance Test Gases > Adjust gases

are California natural gas average compositions

> Substitute gases are representative Pacific Basin LNG compositions

Adjust 1

Adjust 2

Adjust 3

Substitute 1

+ 1.3 %N2

+ 2.1 %N2

+ 5.0 %N2

+ 6.3 %N2

+7.8% N2

+6.4% N2

+3.1 %N2

+2.4 %N2

Substitute 2

California limit, 1385

1300

1320

1340

1360

1380

1400

1420

1440

1000 1020 1040 1060 1080 1100 1120 1140

HHV (Btu/scf)

Wob

be N

umbe

r

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Organizing the Many Industrial Burners

Operating Characteristics Types and Applications Mixing method Radiant Burners

Fuel High Velocity Burners

Oxidant (air, O2, etc.) Regenerative Burners

Draft type Natural Draft Burners

Heating type Boiler Burners

Burner Geometry Linear Grid/In-Duct Burners

O2 and O2-Enriched Air Burners

Flare Burners

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Burner Classes and Sensitivity

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Burners Selected for Testing

Manufacturer Model Name

Comment

Control

Capacity, MMBtu/hr

Radiant Burners

North American Evenglow Radiant Tube Modulating +Pressure Balance 0.02-0.5

Maxon Radmax Radiant Panel On/Off + Venturi mixer 0.025 per head

Bloom Engineering 2320 Recuperative Modulating 0.4 - 0.5

Boiler Burners

Powerflame C1-G-12 Turndown 10:1 Cam linkage + O2 Trim 2-14.7

Cleaver-Brooks SB-200-080-150 Low NOx Packaged System 80HP

LAARS Mighty Term II Hydronic Boiler Staged Control 0.5 – 2.0

Linear/Grid/Duct Burners

Flynn Burner Pipe Linear Burner (baking) Modulating +Venturi mixer 0.04 per inch

Oxygen Enhanced Combustion

Eclipse PrimeFire 300 High Luminosity On/Off + Pressure Balance 0.5 – 8.0

Regenerative Burners

Bloom Engineering 1150 Nozzle-Mixed type Modulating +Pressure Balance To be tested

Nozzle Mixed Burners

Eclipse Combustion ThermJet High Velocity Modulating +Pressure Balance 0.15 - 20

All relevant types are covered; top sellers–by market presence

Lab Testing

Field Testing

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Emissions for Industrial Burners

> Burners tuned to Adjust Gas 2 at 1332 Wobbe, then fired with different adjust and substitute gases

> Emissions vary widely and changes in emissions with Wobbe differ between different burners

0

300

600

900

1200

1500

1800

2100

2400

2700

3000

0

20

40

60

80

100

120

140

160

180

200

1280 1300 1320 1340 1360 1380 1400 1420 1440

NO

x (p

pm) (

corre

cted

to 3

% O

2) [O

xy-G

as]

NO

x (p

pm) (

corre

cted

to 3

% O

2)

Wobbe

Adjust2 Basis

Infrared

Linear

High Velocity

Oxy-Gas

1385 Limit

0

250

500

750

1000

1250

1500

1750

2000

2250

2500

2750

3000

0

5

10

15

20

25

30

35

40

45

50

55

60

1280 1300 1320 1340 1360 1380 1400 1420 1440

CO

(ppm

) (co

rrect

ed to

3%

O2)

[HV,

OG

]

CO

(ppm

) (co

rrect

ed to

3%

O2)

Wobbe

Adjust2 Basis

Infrared

Linear

High Velocity

Oxy-Gas

1385 Limit

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Emissions for Boiler Burners

> Burners tuned to Adjust Gas 2 at 1332 Wobbe, then fired with different adjust and substitute gases

> NOx varies widely based on burner type

> CO is low for all boiler burners and decreases at higher Wobbe

0

5

10

15

20

25

30

35

40

45

50

55

60

1280 1300 1320 1340 1360 1380 1400 1420 1440

NO

x (p

pm) (

corre

cted

to 3

% O

2)

Wobbe

Adjust2 BasisPackagedBoilerBoiler (Field)1385 Limit

0

5

10

15

20

25

1280 1300 1320 1340 1360 1380 1400 1420 1440

CO

(ppm

) (co

rrect

ed to

3%

O2)

Wobbe

Adjust2 BasisPackagedBoilerBoiler (Field)1385 Limit

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Emissions for Radiant Tube Burners

> Burners tuned to Adjust Gas 2 at 1332 Wobbe, then fired with different adjust and substitute gases

> NOx varies widely and decreases with higher Wobbe

> CO can increase exponentially at low excess air levels

0

20

40

60

80

100

120

140

160

180

200

1280 1300 1320 1340 1360 1380 1400 1420 1440

NO

x (p

pm) (

corre

cted

to 3

% O

2)

Wobbe

Adjust2 BasisU-TubeW-Tube (Field)1385 Limit

0

250

500

750

1000

1250

1500

1750

2000

2250

2500

2750

3000

0

1

2

3

4

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6

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8

9

10

11

12

1280 1300 1320 1340 1360 1380 1400 1420 1440

CO

(ppm

) (co

rrect

ed to

3%

O2)

[U-T

ube]

CO

(ppm

) (co

rrect

ed to

3%

O2)

Wobbe

Adjust2 BasisW-Tube (Field)U-Tube1385 Limit

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Conclusions: Industrial Burners

> No industrial burners had ignition problems over the range of gases studied (1308-1425 W)

> Emissions (NOx, CO) can increase, decrease, or be unchanged for burners

> With proper tuning NOx for all burners at 1385 W can be equal to or lower than NOx when burner is tuned to 1332 W

> For burners using low oxidant to fuel ratios (radiant tubes, oxygen burners, low NOx boilers) higher W gas requires increased oxidant to avoid exponential increases in CO

> Many burners require no adjustments for NOx, CO

> Advanced controls can do needed tuning for many burners

> Data suggests simplified protocols can be devised for the remaining burners of concern

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Commercial Cooking Unit Selection

> GTI enlisted Carl Suchovsky, President of Gas Consultants, Inc. and Don Fisher of Fisher-Nickel, Inc. to help select the commercial foodservice appliances

> Selected appliances were representative of equipment currently sold in California

> Appliances represented technology commonly found in restaurants

> Choices covered the burner types found in food service equipment (atmospheric, infrared, powered and fan-assisted burners)

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Commercial Cooking Appliances Selected

Appliance Manufacturer Model Notes

Fryer Frymaster FH155 Infrared burner, exhaust fan

Fryer Pitco SG-14 or SSH55 Atmospheric burner

Convection Oven

Blodgett DFG-100Xcel Atmospheric burner, exhaust blower

Combi Oven Cleveland OGB-6.20 Dual premixed powered burners

Griddle Vulcan 36RRG Atmospheric U-shaped burners

Griddle Jade JSO315 Blue flame burner (cast iron open burners)

Range Garland G36-6R 33,000 Btu/h top burner

Steamer AccumTemp N6 Stainless steel powered burner

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Appliance Test Facility

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CO in Flue Over Wobbe Range of Gases

0

100

200

300

400

500

600

700

800

Mea

sure

d CO

in F

lue

Gas

, pp

mWobbe - 1309 Wobbe - 1385

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NOx in Flue Over Wobbe Range of Gases

0

20

40

60

80

100

120

140

160

Mea

srue

d N

Ox

in F

lue

Gas,

ppm

Wobbe - 1309 Wobbe - 1385

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Food Service Appliance Summary

> No issues with ignition or operation of equipment tested

> Based on NOx and CO emissions appliances can have none, some, or significant interchangeability concerns

─ Some minor concerns with NOx at high Wobbe ─ CO rises to high levels for some appliances at high

Wobbe > Testing of excess O2 in the flue is a good indicator of

high CO and an appliance needing adjustment > Appliances must be either adjusted by manufacturer

or by trained service technician for low emission operation with high Wobbe gas

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Appliance Burner Experiments

> Cooking: 13 cooktops, 12 ovens, 5 broilers > Vented: 5 storage water heaters, 6 tankless , 5 furnaces > Fuels:

─ Northern CA line gas: 1330-1340 WN ─ Simulated LNG: 1390, 1420 WN (some 1360 WN)

> Experimental Approach: ─ Operating cycles to capture transient emission events ─ Duplicate burns for cooktops, ovens, furnaces, storage WHs ─ Varied operation for oven (temp) and tankless (flow) ─ Calculated emission factors for full-burn, end-of-burn ─ Univariate: emissions by burner and fuel ─ Bivariate: emissions related to fuel WN ─ Multivariate: included other effects ─ Changes in emission factor were related to increase in Wobbe Number

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Example Data From Cooktop Experiment

> Pot + 4 L H2O on each corner burner, all at highest firing rates; 15 minute burns

> Cooling period varied in early experiments, then consistent at 15 minutes (CT02, fuel 3A+N2)

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Example Data From Oven Experiment

> Subsequent experiments used 2-3 maintenance cycles per T setting (OV02, fuel 3A)

350 F 425 F 500 F

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Interpretation of Results

Cooking/Unvented Burners

> Indoor exposures > Concern: impacts for individual

burners > Focus on primary pollutants

─ CO, NO2, PN, HCHO ─ Small contribution to ambient air

quality

> Sample includes common technologies, varied ages

> Sample not large enough to reliably assess outliers

Vented Burners

> Ambient air quality > Concern: impacts on total

emissions from population > Focus on regulated pollutants

─ NOX effect on O3, PM2.5

─ CO small effect on ozone ─ HCHO is Hazardous Air Pollutant ─ NO2 primary pollutant

> Most common technologies sampled; results consistent with other studies

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Baseline Emissions* by Appliance Group

CO

(ng J-1)

NO2

(ng J-1)

HCHO

(ng J-1)

PN*

(104 J-1)

NOX

(ng J-1)

Cooktops 7 – 823 5.0 – 17.7 0.1 – 4.7 183 – 9200 25 – 47

Ovens 16 – 528 3.8 – 13.9 0.3 – 5.5 10 – 6300 27 – 41

Broilers 29 – 178 2.8 – 13.0 0.1 – 0.9 107 – 2650 17 – 37

Furnaces <1 – 31 <1 – 9.7 0.2 , 0.4 <1 – 46 22 – 34

Storage WH <0 – 2 0.3 – 2.2 <0.1 3 – 51 24 – 32

Tankless WH 19 – 434 4.0 – 8.9 0.2 – 2.4 <1 – 27 9 – 31

* Range of mean emissions across burners; PN is range of maxima across burners.

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Key Findings: Cooktops

> CO: Increases in most cooktops ─ Significant increases in 11 of 13 cooktops ─ ↑6-40% for 4 cooktops with CO > 100 ng/J

> NO2: Increases in half of the cooktops ─ Significant increases in 7 of 13 cooktops;

↑5-20% ─ All had NO2 > 5 ng/J

> HCHO: Important impacts for some cooktops ─ No change for most burners including

highest emitter ─ Next two highest had one increase 62%,

one decrease 28%

> PN: varies much more with operation than fuel

Effects are change in emission factors (ng/J) per 50 Btu/scf increase in WN

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Key Findings: Ovens and Broilers

> CO: Increases in most ─ Increases in 16 of 17 burners ─ ↑5-40% for 7 of 9 with CO ≥ 100 ng/J ─ ↓5-14% for 2 of 9 with CO ≥ 100 ng/J

> NO2: Increase in half of the burners ─ Increases in 9 burners: ↑10-38% for NO2 > 5 ng/J ─ Decrease of 7% in 1 burner

> HCHO: Some impacts ─ Increases of 8-20% in 6 burners; decrease of 21% in

1 burner ─ No change in 8; no data for 2 burners

> PN varies much more with operation than fuel

Effects are change in emission factors (ng/J) per 50 Btu/scf increase in WN

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Key Findings: Water Heaters I

> Standard storage WHs have low CO and NO2, appear to have low HCHO; negligible fuel effects

> Tankless had higher CO, NO2, HCHO, PN

> Tankless: ─ CO increase for group dominated by unit

with bad regulator ─ Frequency of this problem in population is

unknown ─ NO2 ↑3-19% for 5 burners; ↓3% for 1 burner ─ HCHO ↓2-11% for 5 burners; no change for

1 burner

Effects are change in emission factors (ng/J) per 50 Btu/scf increase in WN

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Key Findings: Water Heaters II

> Storage to tankless switch has much larger impact than LNG on CO, NO2, HCHO

─ Baseline emissions much higher ─ CO and NO2 increase with LNG ─ HCHO decreases with LNG (but higher than storage)

> Baseline NOX lower in tankless water heaters, but more sensitive to fuel WN

─ With LNG, NOX from tankless likely still lower than from conventional storage WHs

─ Given tankless NOX variability, need market analysis

> Effect of fuel WN on ultra-low-NOX storage WHs and next generation tankless?

─ TBD in CEC-funded Healthy Homes study

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Key Findings: Furnaces

> CO: ─ Generally low emission rates ─ ↓26% in 2 furnaces, mixed or no change

in others

> NOX: ─ ↑3-7% in 3 furnaces, no change in other 2

> NO2: ─ ↓14% in 1 furnace; no change in others

> HCHO: ─ Data for only 2 of 5 furnaces tested ─ Relatively low baseline; ↓24-34% with

increasing fuel WN

Effects are change in emission factors (ng/J) per 50 Btu/scf increase in WN

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Appliance Findings: Summary

> Appliance Operation ─ Consistent with other studies, we found no substantial

operational issues related to LNG use in residential appliances

> Pollutant Emissions ─ Small, if any increase in emissions from forced air

furnaces and storage water heaters ─ Tankless water heaters have higher emissions and LNG

impacts compared to storage WHs ─ Cooking burners can have substantial baseline

emissions and sensitivity to LNG

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Connect With Us

Gas Technology Institute 1700 S Mount Prospect Rd, Des Plaines, IL 60018, USA www.gastechnology.org

Contact: David Rue Institute Engineer End Use Solutions

847-768-0508 david.rue@gastechnology.org

Authors: David Rue and Yaraslav Chudnovsky, PhD, GTI; Brett C. Singer, PhD, Lawrence Berkeley National Laboratory; Marla Mueller, California Energy Commission

@gastechnology